<!DOCTYPE HTML>
<style>
body { margin: 0px; }
div.box { padding: 40px; height: 240px; }
#greenyellow { background-color: greenyellow; }
iframe { margin: 0px; border: 0px; width: 240px; height: 240px; }
#frameB { float: left; }
#frameD { float: right; }
</style>
<div class="box" id="greenyellow">
  <iframe src='gesture-tap-mouse-events-between-frames-iframe2.html' id='frameB'></iframe>
  <iframe src='gesture-tap-mouse-events-between-frames-iframe4.html' id='frameD'></iframe>
</div>